Process for welding



' Feb. 13, 1940. E. BAER 2,10,621

PROCESS FOR WELDING Filad May 18, 1938 Jnventor Patented Feb. 13, 1940.

UNITED STATES PATENT OFFICE PROCESS FOR- WELDING Ernst Baer,Berlin-Oharlottenbnrg, Germany, assignor to Robert Bosch Gesellschaftmit beschrinkta' Battling, Stuttgart,

Application In 4Claims.

The present invention relates to the weldin of one or more thin sheetmetal lamellae or foils and a metal carrier.

- In the welding of very thin metal parts, e. g.,

lamellae or foils, and a stronger part serving them as a carrier, bymeans 01' spot welding, there exists the danger that the thin parts willburn away on the passage of current, ii the entire welding currentpasses through them. Oh-

viously a good welded connection cannot be obbears during the weldingprocess both on the thin metal parts, e. g., lamellae or foils, and onthe carrier. In this case, there occurs in fact a branching of thewelding current through the lamellae and the carrier, which causes adecrease oi the current heat on the thin metal parts.

The invention is more particularly described with reference to theaccompanying drawing, in

which- Figure 1 shows the welding 01 a number of thin lamellae with athicker metal sheet, and

Figures 2 and 3 show a cartridge condenser 01 which the metal coatings,connection electrodes and feed wires, which project at the ends, arewelded by the process according to the invention. In Figure l, a. is acopper sheet 1 mm. thick, with which a number of brass lamellae 0.1 mm.thick, which are placed one above the other, are

r to be welded. As will be seen from the drawing,

the lamellae b are placed stepwise one above the other upon the sheet ain order that the welding electrode c may beat as far as possible on allthe lamellae b. .The copper sheet a. is in contact with the weldingelectrode cat the point I d. In order that the contact surface may be aslarge as possible, the welding electrode 0 is rounded on here, and thusits shape is adapted to the position of the sheet a and the lamellae 6relative to each other. The second welding electrode e is placed uponthe lower side oi the sheet b.

In the case of the cartridge condenser shown in Figures 2 and 3, 1 arethe metal coatings pro-' Jecting at the ends of the winding, and theyconsist ofthin aluminium i'oils (thickness about 0.006

mm.) and are to be welded to the electrode a.

The electrode 9 consists of copper sheeting havinga thickness of about0.05 mm. In this case, according to the invention both the rod-shapedwelding electrodes h of the welding machine are so set up during thatthey bear both on' the toils t and onthe electrode a. The supthroughsaid welding electrode,

May 18, 1938, Serial No. 208,693 Germany May 18, 1937 the electrode 9.Thus, according to Figure 3,

the cylindrical electrode sheet a is first pressed flat by the weldingelectrodes h. Thus it has been made possible by the process according tothe invention to make a completely satisfactory welded connectionbetween the foils f, the electrode g, and the connecting wire 1' in onework step.

I declare that what I claim is:

l. A process for welding a plurality of thin sheet metal lamellae orfoils, and ametal carrier by spot welding, comprising arranging saidlamellae in superposed relation so that an end portion oi each lamellaeis exposed, setting up an electrode so that prior to and during thewelding process it bears both on the said lamellae and on the carrier,and passing afwelding current through the electrode, lamellae andcarrier.

2. A process for welding a series of thin sheet metal lamellae or foilsand a metal carrier by. spot welding, comprising arranging said lamellaestepwise one above the other, setting up an electrode so that during thewelding process it bears both on the lamellae and on the carrier, andpassing an electric current through said lamellae, carrier andelectrode. 1

3. A process for Welding a plurality of thin sheet metal lamellae orfoils by spot welding, comprising arranging said lamellae stepwise insuperposed relation so that each lamella is exposed, contacting anelectrode with said lamellae so that during the welding operation itbears against the exposed end portions of all of said lamellae, andpassing an electric welding current through said lamellae and saidelectrode. 4. A process for. electrically connecting, by welding,.aterminal wire connection, a terminal electrode and the terminals of thinsheet metal an end portion of lamellae or foils oi! an electricalcondenser, com,-

prising arranging said lamellae stepwise one above the other on saidterminal electrode, contacting said terminal electrode and said terminalwire connection, setting up a welding electrode so that during thewelding operation it bears both on the lamellae and on said terminalelectrode, and passing an electric welding current nal electrodeandterminal wire connection.

. ERNST lamellae, termi-

